A229529 Number of defective 3-colorings of an n X 3 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.

2, 8, 58, 356, 2038, 11184, 59626, 311260, 1598974, 8110984, 40726290, 202778804, 1002549414, 4926990688, 24088644794, 117243591052, 568394827598, 2745949068600, 13224557927522, 63511978473572, 304253006899190

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 10*a(n-1) - 29*a(n-2) + 20*a(n-3) - 4*a(n-4) for n>5.

Empirical g.f.: 2*x*(1 - 6*x + 18*x^2 - 16*x^3 + 4*x^4) / (1 - 5*x + 2*x^2)^2. - Colin Barker, Sep 18 2018

Example

Some solutions for n=4:
..0..1..2....0..1..2....0..1..0....0..1..0....0..1..0....0..1..2....0..1..2
..0..1..2....0..2..0....0..1..0....1..2..0....0..1..0....0..2..0....2..0..2
..2..1..2....0..2..1....0..1..0....0..2..1....1..2..0....0..2..0....1..0..1
..1..0..2....1..2..0....0..2..2....1..2..1....0..2..0....0..2..1....2..0..1

Crossrefs

Column 3 of A229534.

Sequence in context: A153553 A334617 A191481 * A007347 A027257 A308352

Adjacent sequences: A229526 A229527 A229528 * A229530 A229531 A229532

Keyword

nonn

Author

R. H. Hardin, Sep 25 2013

Status

approved